<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.netfluke.sergey.greeter.MainActivity">

    <TextView
        android:id="@+id/txtV"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Howdy neighbor!"
        android:textSize="32sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        />


    <Button android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Press this!"
        android:id="@+id/button2"
        android:onClick="onButtonClick"
        />

    <!-- Remove android:onClick="onButtonClick" to see what happens when
          the button's callback is not connected to the activity -->

</android.support.constraint.ConstraintLayout>
